Former tomato grower pleads guilty in marijuana greenhouse caseA 64-year-old former greenhouse tomato grower in California has pleaded guilty to conspiring to grow at least 50 marijuana plants. His 63-year-old brother is expected to reach a similar plea agreement with federal prosecutors.

Thomas Jopson, 64, pleaded guilty to the lesser charge in exchange for two other federal criminal growing charges being dropped. The initial charges two federal felony counts of manufacturing at least 1,000 marijuana plants could have each resulted in 10 years to life in prison and up to a $5,000 fine for Jopson.

According to his plea agreement, filed in federal court in California"s Eastern District, the lesser charge could carry a sentence of up to 20 years in prison and/or a fine up to $1 million or supervised release of three years to life.

The U.S. Attorney prosecuting the case stated in the plea agreement that the government would seek a sentence in the low-end of the possible range. Sentencing is set for June 24.

Thomas Jopson"s brother David Jopson, 63, is set to appear in court on Feb. 18, when he is expected to enter a guilty plea based on a plea agreement.

The brothers, who originally grew rice, started growing heirloom tomatoes at their Rio Oso, Calif., greenhouse operation in 2008, according to court documents.

When tomato prices dropped, the brothers entered a growing agreement with Yan Ebyam to grow medical marijuana. The Sacramento Bee reported the Oakland, Calif., man"s first name stands for "yes and no" and his last name is "maybe" spelled backwards.

A multi-agency investigation that began in 2011 resulted in grand jury indictments of the Jopson brothers, Ebyam and six other people. A March 3 trial is set in Ebyam"s case.